Southampton draw Vitesse
Saints manager Ronald Koeman began his managerial career with Vitesse, who finished fifth in the Dutch Eredivisie last season.
Vitesse have Chelsea’s England U20 captain Lewis Baker on loan next season as part of an informal partnership arrangement between the two clubs.
West Ham and Inverness could play an all-British Europa League qualifier if the two sides come through their second-round qualifying ties.
The Hammers hold a 1-0 lead over Maltese side Birkirkara while Inverness are a goal down to Astra of Romania.
Aberdeen will travel to FC Kairat Almaty or Alashkert if they beat NHK Rijeka.
Full draw (ties to be played July 30 and August 6):
FC Zurich v Cherno More/Dinamo Minsk
Kairat Almaty/Alashkert FC v Rijeka/Aberdeen
Dacia/MSK Zilina v Vorskla
AZ v Istanbul Buyuksehir BSK
Bordeaux v AEK
Lokomotiva Zagreb/PAOK Salonika v FC Spartak Trnava/Linfield
Sampdoria v Vojvodina/FK Spartaks Jurmala
Liberec v Hapoel Kiryat Shmona
Athletic Bilbao v FH Hafnarfjordur/Inter Baku
ASA Targu Mures v St Etienne
FK Kukesi/Mladost Podgorica v Legia Warsaw/Botosani
Cukaricki Belgrade/Gabala v Apollon Limassol/Trakai
FK Jelgava/Rabotnicki Kometal v Trabzonspor/FC 03 Differdange
Skonto FC/Debrecen v KR Reykjavik/Rosenborg
Charleroi/Beitar Jerusalem v FC Zarya Lugansk
Shakhtyor/RZ Pellets Wolfsberger AC v Borussia Dortmund
Beroe/Brondby v Jagiellonia Bialystock/Omonia Nicosia
Jablonec v FC Copenhagen/Newtown
SK Sturm Graz v Rubin Kazan
AIK/Shirak v Atromitos
SCR Altach v Guimaraes
Hapoel Beer Sheva/FC Thun v FC Vaduz/Nomme Kalju
Randers FC/IF Elfsborg v Shamrock Rovers/Odd
Standard Liege v Ferencvaros/Zeljeznicar Sarajevo
Koper/Hajduk Split v Mlada Boleslav/Stromgodset
Belenenses v Slask Wroclaw/IFK Goteborg
Southampton v Vitesse
West Ham/Birkirkara v Inverness CT/FC Astra Giurgiu
Krasnodar v Slovan Bratislava/UCD